In Japan, car navigation systems are widely distributed. Many navigation systems, which are not only for cars, have been developed that select and display the optimal path from a current position to a destination. However, there are surprisingly few navigation systems that give the user the freedom to choose a path.
For example, Patent Document 1 discloses a position information providing system that generates and displays, as ambiguous position information, a polygon region that indicates a block (a region surrounded by roads, a city block) including the current position so as to display the current position ambiguously when displaying the position. In Patent Document 1, as compared to the case of displaying the current position with a dot on a map, the position information of the current position of the owner of a terminal device can be displayed using ambiguous position information that covers a certain range, so that the owner of the terminal device is provided with many selectable paths within a certain range.
Furthermore, Patent Document 2 discloses an area entering/exiting information notifying system in which when setting an area where a person to be determined is present, an arbitrary region can be registered as the area using a polygon in addition to a circle and a polygonal shape. Patent Document 2 is characterized in that when entering into/exiting from the region registered as the area is confirmed, the display mode of said region is changed to display it. That is, since the current position of the person to be determined can be grasped on an area basis, which path to select and travel is left to be determined by the person to be determined.